Sprint Nextel Corp. will begin selling the iPhone 5 in mid-October, sources close to the matter tell the Wall Street Journal.

Another source tells the Wall Street Journal that Sprint will begin selling the iPhone 4 concurrently with the iPhone 5. The iPhone 5 is expected to be similar to the iPhone 4, but the new phone will include an improved operating system and a thinner model.

The news should benefit Sprint, who has struggled in the midst of a poorly regarded merger with Nextel Corp. and a lagging customer base compared to rivals. Sprint, with 52 million customers is the third largest wireless carrier in the United States, with far fewer customers than leaders Verizon (106 million) or AT&T (99 million), who both sell the iPhone. Sprint has opposed a merger deal between AT&T and T-Mobile USA out of concern that the merger will affect competition in the wireless industry.